Al-Kāfi
Hadith 1094ـ مُحَمَّدُ بْنُ يَحْيَى عَنْ أَحْمَدَ بْنِ مُحَمَّدِ بْنِ عِيسَى عَنْ مُعَمَّرِ بْنِ خَلادٍ قَالَ سَمِعْتُ أَبَا الْحَسَنِ الرِّضَا (عَلَيهِ السَّلام) يَقُولُ لَيْسَ الْعِبَادَةُ كَثْرَةَ الصَّلاةِ وَالصَّوْمِ إِنَّمَا الْعِبَادَةُ التَّفَكُّرُ فِي أَمْرِ الله عَزَّ وَجَلَّ.
4. Muhammad ibn Yahya has narrated from Ahmad ibn Muhammad ibn ‘Isa from Mu’ammar ibn Khallad who has said the following: “I heard abu al-Hassan al-Rida (a.s.) saying, ‘A great deal of prayer and fasting only are not (everything in) worship. Worship is only in thinking about the affairs of Allah, the Most Majestic, the Most Holy.’”